Importance of Hot Spots in Gold Nanostructures on Direct Plasmon-Enhanced Electrochemistry

Abstract

Recently, the direct utilization of plasmonic metal nanostructures in accelerating the electrochemical reactions reveals the importance of hot charge carriers generated by localized surface plasmon resonance (LSPR). However, the effect of morphological forms of the same metal element on direct plasmon-enhanced electrocatalytic activity has not yet been well documented. Herein, four kinds of Au nanostructures with different morphologies of nanospheres (NSPs), nanorods (NRs), nanostars (NSs), and triangular nanoplates (NPLs) were synthesized. The shape-dependent plasmonic enhancement effect of Au nanostructures toward the electrooxidation of ascorbic acid (AA) was studied. We find that the electrochemistry of AA oxidation on these Au nanostructures can be enhanced upon light irradiation with the higher enhancement effect of the Au NPLs and NSs than the Au NSPs and NRs. This shape-dependent enhancement effect is suggested to be related to the number of “hot spots” in different NP surfaces generated from Au LSPR. Thus, the present work would shed new light on the direct plasmon-enhanced electrochemistry, which helps in widening the potential applications of plasmonic materials in electrochemical sensors and electrochemical energy conversion.

Optical Resonator Enhanced Photovoltaics and Photocatalysis: Fundamental and Recent Progress

“…Many configurations and shapes of metal nanoparticles have been fabricated and studied in photocatalysis. [193,[202][203][204][205] Many factors contribute to photocatalytic performance enhancement, including the formation of local electric field, light absorption enhancement due to SPR, and charge carriers generation improvement. [28] In 2018, Jeong et al demonstrated silver nanoparticles embedded in BiVO 4 nanocomposite photoanode to enhance photocatalytic current densities, as shown in Figure 13a.…”

Plasmon-Induced Electrocatalysis with Multi-Component Nanostructures

“…Over the last two decades, a great deal of research has been devoted to the development of nanostructured materials for improved electrocatalysis (Table 1). It is now well established that next to morphology, the size and shape of the nanomaterials are considerably affecting the overall electrocatalytic activity of such systems [5,27]. All of the developed systems focused on electrocatalysis in the dark or under daylight, and a wealth of information on the structure/activity relationship of electrocatalysis on light-induced resonant phenomena have been neglected.…”

“…Gold nanoparticles decorating glassy carbon electrodes [4,5] as well as gold nanofiber-based electrodes [11] have been proposed for plasmon-induced electrochemical processes. Wang et al underlined the importance of hot spots in Au NSs on direct plasmon-enhanced electrochemistry using the oxidation of ascorbic acid as a model [5]. He suggested that an increased number of hot spots, as observed on gold nanostars (Au NSs), results in the best plasmon-enhanced electrochemistry effects.…”

“…These selected examples revealed that harvesting energy from the hot charge carriers of plasmonic structures is promising for energy conversion and photocatalysis alike, paving the way for developments of various catalytic reactions. Most attention has been devoted to plasmon-mediated chemical transformations, and a few reports have investigated plasmon-enhanced electrochemical transformations [4,5,6,7,8,9,10,11,12,13,14]. The progress that has been achieved in the synthesis of materials that are useful for the direct plasmon-accelerated electrocatalysis as well as on metal/semiconductor composites will be outlined here, with the belief that the application of new concepts of electrocatalysis is essential for the advancements of many industrial electrocatalytic processes.…”

Plasmon-enhanced electrocatalytic oxygen reduction in alkaline media on gold nanohole electrodes

“…7 Surprisingly, there are only a few reports on plasmon-enhanced electrochemical reactions using the intertwined plasmoncatalytic-electrochemical properties of gold nanostructures. [8][9][10] . Minteer and co-workers fabricated Au nanofiber-based electrode for plasmon-enhanced electrocatalytic oxidation of ethanol and methanol in alkaline media.…”